This invention relates to the gasification of coal and more particularly pertains to an apparatus for the partial combustion of coal with oxygen or gas containing oxygen which allows continuous gasification without the ash content of the coal presenting any problems.
Over the years, a number of processes and apparatus have been developed for coal gasification to take into account many variable factors including, by way of example, the source of coal employed, the gasifying medium employed, the ultimate use to be made of the product gas and the like. In this context, coal is taken to comprise a great variety of free-carbon-containing fuels, such as anthracite, bituminous coal, brown coal, lignite, soot, coke, etc. Additionally, many of these known processes and apparatus have been devised and employed to produce a product gas comprised primarily of carbon monoxide and hydrogen. Such product gases are extremely useful as a fuel, whether further treated or not, and are important base materials for chemical syntheses such as the preparation of ammonia and hydrocarbons.
While known coal gasification processes and apparatus may differ in a variety of ways, all are presented with the common problem of removing the non-carbonaceous, mineral residue produced during gasification from the reactor apparatus. Without the employment of special precautions the residue, or ash content, may accumulate in undesirable places in the gasifier apparatus thereby adversely affecting the gasification. These problems vary with the type of residue formed, e.g. dry ash or molten slag, and are particularly prevalent with molten slag.
An additional problem associated with conventional gasification techniques and apparatus resides in supplying the coal and gasifying medium to the gasification reaction zone. Inasmuch as gasification is usually carried out at extremely high temperatures, i.e., usually above about 1400.degree. C. to about 2700.degree. C., any supplying means, such as reactor inlet tubes or the like, subjected to such temperatures may become superheated which may result in mechanical problems or otherwise adversely affect the continuous supply of the coal and gasification medium to the reactor.